Using the Subaru, Keck, and Gemini telescopes, astronomers have discovered a young cluster of galaxies in the early Universe. Named z66OD, the protocluster contains at least 12 huge galaxies and is 13 billion light-years away. It is the earliest galaxy protocluster ever observed, meaning such large-scale structures were around very early in the Universe’s existence. The z66OD protocluster: the blue shading shows the calculated extent of the protocluster,...